Friends,


My 04 Duramax makes a clunking noise when I drive over uneven pavement at slow speeds. I've read about the leaf spring "slap" and related fix. However, I don't think this is my problem. My leaf springs have the black rubber/plastic cookies on both ends between the bottom leaf and the next one. My understanding is that these come off sometimes, allowing the leafs to "slap" against each other and make a racket. If you think this may be my problem (even with my black spacers in place) please let me know.


My noise sounds more like a clunking. Like something in the suspension is loose? The GMC dealership wouldn't help me under warranty, because I have step tubes (Boss Bars). Although the tech suggested it might be the mounting hardware for the step tubes or body mount bolts, some of which were replaced by parts in the nerf bar kit. I don't think it's this, because all the hardware is snugged up pretty good.


I've done several searches for noises, but have been unable to find something else to check.

my leafs were replaced once for that.. then the noise went away. i notice the springs get warped and loose and they clack when you go over uneven surface or a speed bump at an agle... loosen and tighten the 4 bolts that hold the leaf springs to the axle. that might help.